First redesigned thrust reverser delivered for 737 Max

Spirit AeroSystems has delivered the first thrust reverser to Boeing for engines on the 737 Max that features a key component redesigned to meet the programme's lofty production ramp-up targets.

The Wichita-based supplier now builds a composite inner wall for the thrust reverser along with a thermal protection system, replacing a titanium honeycomb material used on previous 737 Max engines.

Last year, Boeing switched to the composite part after concerns grew that the previous supplier, GKN, would be unable to keep up with Boeing’s plans for a rapid production ramp-up on the 737, which will grow to more than deliveries per month within four years.

Spirit also completed an expansion at the company’s manufacturing complex in Wichita to build the composite inner wall component for the 737 Max. The 94,000ft2 expansion is sized to deliver 94 thrust reversers per month, matching Boeing’s planned rate increase to 47 737s per month in 2017.

“Spirit helped design and develop a technical solution for our customer and now we have the capacity to deliver the product on time and with the highest quality possible,” says Duane Hawkins, Spirit's senior vice-president of Boeing Programmes.

Spirit, which was spun-off from Boeing in 2005, supplies 70% of the 737 airframe, including the fuselage, thrust reverser, pylons, engine nacelle and wing leading edges.

A new thrust reverser design was required to accommodate the 737 Max’s new CFM International Leap-1B engines, which feature a 21.3cm (8.4in) wider fan diameter and significantly higher internal temperatures. Boeing originally switched to GKN’s titanium honeycomb material for the inner wall to keep the width of the thrust reverser as small as possible while still being able to withstand the higher temperatures introduced with the Leap engine.

But Spirit proposed a composite material that meets size and thermal requirements, while also being designed to accommodate the programme’s manufacturing rate targets.